Automatic surgery retractor

ABSTRACT

An automatic surgery retraction apparatus which is selfsupporting away from an operating table or a patient and is selectively positionable along both. The apparatus includes a vertically extensible upright assembly mounted for rotation about a base member and a horizontally extensible boom assembly mounted for pivotal movement about the upright assembly. The upright and boom assemblies are provided with electronic precision servopositioning systems allowing remote actuation thereof for precise and accurate positioning. The boom assembly is provided with one or more disposable strap members carrying retraction instruments, which may also be disposable.

1 AUTOMATIC SURGERY RETRACTOR BACKGROUND OF THE INVENTION 1. Field ofthe Invention The present invention relates to surgical apparatus andmore particularly to surgical retractor apparatus.

2. Prior Art Various surgical retractor apparatuses are known. Certainof such known apparatuses simply comprise an instrument means forinsertion into a patient and a handle means which must be continuouslyheld at a given position by a suitably trained individual. These typesof apparatuses have many disadvantages including the fact that theyrequire a high degree of stamina by the individual utilizing them andnecessitate the presence of a nonsurgeon individual at the operatingtable. Other known apparatuses comprise various framelike members whicheither attach to the operating table or to the patient and fixedlysupport an instrument means for insertion into the patient. Any and alladjustments for such apparatuses must be manually effected. These typeof apparatuses also have many disadvantages including the fact that theyare cumbersome, inefficient and require the surgeon or an assistant toeffect the necessary adjustments as the operation progresses.

SUMMARY OF THE INVENTION The invention provides an automatic surgeryretractor apparatus which is self-supporting away from an operatingtable or a patient and is selectively and precisely positionable inrespect to the patient and the operating table. Generally, the apparatusincludes an extensible upright assembly rotatably mounted on a movablebase member. In certain embodiments, a track means is provided along thefloor of an operating room in working relation with the base member inguide the apparatus along a given path. In other embodiments, the basemember is provided with lockable wheels or the like allowing theapparatus to be selectively moved to a given position and secured. Anextensible boom assembly is pivotally attached to the upper portion ofthe upright assembly for angular movement along both the horizontal andvertical planes. One or more disposable strap members are attached to anend of the boom assembly and each strap member carries the desiredretraction instrument for insertion into a patient during a particularoperation. Suitable precision servo positioners, such as transistorizedreversible electronic motors, are provided for the various members ofthe apparatus and which are energized by suitably positioned controlpanels.

Prior to the start of a particular operation, the apparatus of theinvention is moved into a desired position away from the operating tableand suitably secured to locked in place. The upright assembly isextended to an approximate desired height and the boom assembly isextended an approximate desired distance. The upright assembly is thenrotated out of the way. The patient is then brought in and suitablypositioned on the operating table and secured thereto as desired and theoperation begun. At this time the disposable strap member is removedfrom a suitable sterilized container and attached to the boom assembly.The upright assembly is then rotated into a properly aligned positionand suitable retraction instruments are attached to the strap members.Although the strap members and the retractor instruments can bepreassembled and sterilized as a unit. The retractor instruments arethen inserted into the operation incision and the boom assemblyretracted sufficiently to maintain the desired degree of opening. Duringthe course of the operation, the various members are preciselyadjustable as desired from a remote control panel and the area aroundthe operating table is free for the surgeon and his assistants who areactively involved in the operation. Various safety features, such aslocks, brakes, alternative energy circuits, electrical insulator means,etc. can be provided as desired.

BRIEF DESCRIPTION OF THE DRAWINGS FIG. 1 is an essentiallydiagrammatical top view of an apparatus constructed and operated inaccordance with the principles of the invention;

FIG. 2 is an elevational side view, partially broken away, of anembodiment of the apparatus of the invention;

FIG. 3 is a top view, partially broken, of an embodiment of thedisposable strap member carrying an embodiment of a retractioninstrument in accordance with the principles of the invention;

FIG. 4 is a partial side elevational view of the device illustrated atFIG. 3;

FIG. 5 is a partial top view of a disposable strap member carryinganother embodiment of a retraction instrument in accordance with theprinciples of the invention; and

FIG. 6 is an essentially schematic diagram representing an embodiment ofa control circuit utilized in the invention.

DESCRIPTION OF THE PREFERRED EMBODIMENTS Throughout the various Figures,like reference numerals will be utilized to refer to like parts.

As shown in FIG. 1, a plurality of apparatus embodiments l1 constructedin.accordance with the invention are simultaneously usable in a givenoperation to maintain an incision in a desired open position. Each ofthe apparatus 11 is positioned away from an operating table 16 asuitable distance whereby the surgeon and his assistants haveessentially free and adequate access to all portions of the table 16and/or a patient 17. Track means T are provided and are suitablyrecessed into the floor as a safety feature and to provide a guide pathalong the edge of the table 16. As illustrated, only one side of theoperating table has a track means T while the other side is without anypredetermined guide path. The guide path provided by the track T is hereillustrated as a straight line, however, the path may be curved asdesired.

Each of the apparatus 11 has a movable base member adapted to supportthe various other apparatus members thereon. A suitable means, such aswheels or ball bearings, are provided along the bottom of the basemembers 1 la for selective movement of the apparatus along a given path.Of course, track means may be provided for all of the apparatus or maybe dispensed with, however, it has been noted that track means provide amore positive guiding means allowing better positioning of theapparatus. A control panel C id mounted along one end portion of thebase member 11a and has a plurality of control knobs or the like Ca forselective energization and adjustment of the apparatus. When desired,the control panel C may bepositioned remote from the apparatus 11, suchas at an end of the operating table 16 and, a suitable single controlpanel may be provided for a plurality of apparatuses as desired.

A vertically telescoping or extensible (i.e., axially movable) uprightassembly 12 is fixedly attached to the base member 11a and mounted forrotation or angular movement about its longitudinal or vertical centralaxis for angular positioning in respect to the base member 110 asdesired. Safety means (not shown) are provided to maintain the uprightassembly in a given position, both as to its angular and axialpositions.

A horizontallyY telescoping or extensible (i.e., axially movable) boomassembly 13 is fixedly attached to an upper end of the upright assembly12 in a pivotal manner so as to allow the boom assembly 13 to pivotabout its point of attachment. The boom assembly 13 includes and isprovided with a selectively extensible arm member 14. Safety means (notshown) are provided for positively maintaining the boom assembly 13 in agiven position, both as to its angular and axial position. A safetyattachment means 15 is fixedly attached to an outer end of arm member 14and a plurality of disposable strap members 19 are selectively securedto the attachment means 15 via a yoke member 15a.

The disposable strap members 19 are provided with suitable retractioninstruments 20 for insertion into an incision 18. As

will be appreciated, a variety of retractor instruments are known andany particular type of retractor instrument is readily attachable to thedisposable strap means 19. For most general operations where relativelysimple incisions are sufficient, a standardized retraction instrument,such as a curved blade member, is provided as a unit with a disposablestrap member, and in accordance with the invention such a unit isdisposable thereby materially simplifying sterilization problems.Preferably, the strap members 19 are composed of a suitable syntheticresin material, such as a polyester material (i.e., Mylar, a registeredtrademark of E. I. duPont de Nemours & Co., for a polyester filmmaterial) suitably treated, as by molecular orientation or byperforation or the like, to exhibit selectively limited tensilestrength. The strap members 19 may also be composed of a suitable fabricor a combination of fabric and resin material so as to be economicallydisposable and easily sterilized as required. In instances where theretractor instrument is formed as a unit with the strap members so as tobe disposable therewith, it may be composed of a suitable syntheticresin material, such as a nylon or polycarbonate material.

As shown, the retractor instruments 20 are inserted into the incision l8and the arm members 13 are retracted by actuation of their respectivemeans for accurately and speedily positioning the members so as toprovide a desired amount of tension on the strap members 19 and maintainan opening at the incision. As the operation progresses, the position ofthe retractors can be moved as desired and the position of the variousunits 11a, 12, 13 and 14 can also be precisely adjusted by.selectiveenergization of their respective precision servopositioning means.

FIG. 2 illustrates an embodiment 21 of the apparatus constructed inaccordance with the principles of the invention. A base member 11a ismounted on a plurality of wheels 22. As diagrammatically indicated at B,a brake-locking mechanism is provided in working relationship with thewheels 22. The base member is formed into a suitably sized cabinet andthe upper free surface thereof may be utilized as a work area forcarrying surgical instruments and the like. A control panel C is mountedat one end of the cabinetlike member 11a along a portion thereof and hassuitable control devices (not shown) for remotely and selectivelyenergizing the various power means of the apparatusA suitable powersource (not shown) is provided in working relation to control panel C soas to provide energy to the various drive means of the apparatus.

A reversible drive means Ml, such as a reversible DC electrical motor,is mounted interiorly of the base member 110. The drive means M1 isprovided with suitable energization circuit (best seen in FIG. 6)interconnected to a communication means, such as electrical wires W, soas to provide an energy flow path between the drive means M1 and thecontrol panel C and to a suitable power source (not shown). Aspeed-control device 23 is mounted in working relation with the drivemeans M1 and with one of the wheels 22. A plurality of belts 230 or thelike are provided to transmit the power from the motor means M1 to thespeed control device 23 and then to the wheels 22.

A suitable recessed track means T is provided on the operating roomfloor and disposed along a desired guide path. The wheels 22 engage thetrack in a working relation and are positively guided thereby along thedesired guide path.

An upright cover member 24 is centrally mounted onto the upper outsidesurface of the base member 11a in a fixed manner. An opening 24a isprovided along the upper surface of cover member 24.

A rotatably supported collar assembly 26 is mounted interiorly of thecover member 24 and on top of the base member 11a. The support collarassembly 26 includes a rigid low baseplate 26a directly attached to thebase member 11a and an upper angularly movable support plate 26b. Thesupport plate 26b is provided with a central through opening (notshown). A rotatable means 26c, such as a wheel, separates the plate 26aand 26b and allows the support plate 26b to rotate relative to the lowerplate 26a. The lower surface of the support plate 26b is provided withan engagement surface, such as a suitably geared track, along theperipheral edges thereof for positively driving the plate 26b in arotary motion. A suitable drive means M2, such as a reversible DCelectronic motor, is mounted on the base member 11a in workingrelationship to the collar assembly 26. A spur gear 27 or the like ismounted on the output shaft of the drive means M2 so as to engage thegear track or the like with the support plate 26b. In this manner, theplate 26b is selectively rotated about the vertical axis to any desiredangular position. As will be appreciated, the drive means M2 is alsoprovided with a suitable energization circuit and with suitablecommunication means for interconnecting the circuit with the controlpanel C.

The upright assembly 12 comprises an outer rotatable column member 25which is mounted on the upper surface of the support plate 26b so as tobe generally concentric with the through opening in the plate 26b. Theouter column member 25 is hollow along its lower portion so as to definea lower receiving chamber. The upper end of the outside column member 25is closed, as by a cap means 25a and a rod member 31 is rigidly securedthereto. The outer column member 25 is angularly positionable as desiredand rotates with the support plate 26b.

An inner stub member 29 is mounted centrally within the receivingchamber (i.e., the lower portion) of outer column member 25 and passesthrough the opening in plate 26b for direct attachment with the plate260. The stub member 29 is fixedly attached andprovides an anchoringmeans between the base member 11a and the upright assembly 12. Suitablebearing means are provided between the outer walls of stub member 29 andthe bottom of the through opening of plate 261: so as to allow relativemovement therebetween.

A support bracket S is rigidly mounted along the outer surface of thecolumn member 25 so as to support a drive means M3 along an outer sidesurface of column member 25. The support means S extends beyond thedrive means M3 so as to provide a guide support for an axially movablerod member 33. If desired, a plurality of support means may be provided.

, The drive means M3 is a reversible DC synchronized electronic motorprovided with a suitable energization circuit and with communicatingmeans, such as wires W interconnecting the circuit with the controlpanel C. A motion translation device 34, such as worm gear or the like,is mounted on the output shaft of the drive means M3 as shown.

The axially movable rod member 33 is pivotally attached, as at P to thehorizontal boom assembly 13 and extends downwardly therefrom in aworking relationship with the motion translation device 34. The rodmember 33 is provided with a rack means 33a along one surface thereoffor engagement with the device 34 whereby energization of the drivemeans M3 drives the rod member 33 in an up-and-down motion as desired. Asafety retaining means 33b is provided along the lower end of rod member33 to insure that no disengagement occurs. A further safety featureincludes the fact that positive mechanical engagement between the drivemeans and the rod member is continuously maintained during alloperations positions so that no slippage or the like can occur.

The horizontal boom assembly 13 includes an outer sleeve member 35 andan inner axially movable arm member 14. The sleeve member 35 is providedwith a pair of projecting ear members 34a and 34b for attachment withthe rod members 31 and 33 of the upright assembly 12 so as to providepivot points P of attachment allowing the horizontalboom assembly 13 topivot in a vertical plane about the upright assembly 12. As shown, thehorizontal boom assembly is free to rotate through an angle 0 of about60 to however, by appropriately shaping cover member 24 greater angularmovement is possible as desired.

Inner arm member 14 is mounted in a linearly movable manner within thesleeve member 35 so as to be extensible and retractible therein asdesired. The arm member 14 is provided with a rack means 14a to engagewith a motion translation device 36 such as a worm gear, to effect thedesired extension or retraction. A safety retaining tab 14b is securedto the outer end of arm member 14 to prevent the arm member from beingdisengaged with the motion translation device 36.

A servo-positioning means M4 is mounted along one end of the sleevemember 35 and is provided with a suitable energization circuit andappropriate communicating means interconnecting the drive means M4 withthe control panel C. It will be noted that the communication meansbetween the various means M1, M2, M3 and M4 are shown as passinginternally of the structural members. This type of arrangement isconvenient to avoid entanglement of the wires. The means M4 is providedwith a motion translation device 36, such as a worm gear or the likedirectly connected to its output shaft and arranged to engage or meshwith rack means 14a of arm member 14.

A safety attachment means 15 is secured to the nondriven end, or thesecuring end, i.e., the end not in engagement with means M4, of armmember 14. The attachment means 15 include a warning means 41, such as aself-energizing light (i.e., containing an appropriate sized dry cellbattery positioned remote from the arm member 14) for selectiveactuation and indicating an excess pressure being applied. Attachmentmeans 15 is formed into the shape of a hollow cylinder. An internallymounted tensioning means 42 is mounted, such as a helical spring or thelike within attachment means 15 and includes a means 42a of adjustingthe tension thereof as desired. The tension means 42 is provided withconventional contact points to complete the circuit of warning device 41as it is moved to a given position.

A yoke member 15a is directly attached to the tensioning means 42whereby any tension on the yoke means 15a is directly transmitted to thetensioning means 42. The yoke means 15a may comprise a transverselyextended barlike member with a dimension sufficient for carrying aplurality of disposable strap means. As shown, a plurality of strapmeans 19 may be directly attached to the yoke member 15a in asubstantially uniformly spaced manner. The disposable strap means 19 areprovided with suitable retraction instruments for use in a particularoperation.

As best seen at FIG. 3, the disposable strap 19 comprises an elongatednarrow band of material 45, such as a synthetic resin, a fabric, or acombination thereof. Preferably, the material 45 is selected to havelimited tensile strength and is provided with means 46, such asperforations, positively providing such limited tensile strength. Thisadditional safety feature is to further insure that only limited tensionwill be applied to the incision. The perforations 46 are uniformlyspaced along the length of the disposable strap member 19 and alsofunctions as an adjustment means of lengthening or shortening the strap19. At both ends of disposable strap member 19 are provided a pair ofpostlike projections 47 for insertion and mating with the perforations46 so as to provide approximate length adjustability for the strapmembers 19. In this manner, the perforations 46 serve a dual function ofproviding desired tensile strength characteristics to the strap member19 and providing a means, along with posts 47, of adjusting the lengthof the strap member 19. Further, as shown, the perforation means 46 andpost means 47 also serve as an extremely efficient means of fasteningretractor instruments 20 to the strap member 19.

The retraction instrument 20 may comprise a body portion 20a having asuitable recess 48 along one edge thereof of a sufficient size toreceive the strap member 19 therethrough as shown. The other end of theretraction instrument 20 is adapted to function as a blade portion 49.Such blade portion may be integrally formed with the body 20a or may beseparately attached as desired.

FIG. 5 illustrates another embodiment 50 of a retraction instrument. Theembodiment 50 comprises a main body portion 5l having a plurality ofblade portions 52 dependent therefrom so as to provide a somewhat widerarea of contact with an incision. The body 51 is provided with asuitable recess 51a for receiving a disposable strap member 19 asexplained hereinbefore.

In certain instances, it is desirable to form the retractioninstruments, such as the embodiments 20 or 50, of a suitably economicalmaterial so as to allow them to be disposable with the strap member 19.In such instances, the retractor instruments may be formed of suitablyrigid synthetic resin material, such as polycarbonate resins orpolymeric amide resins, i.e., nylon. Further, suitably shaped disposableretractor instruments may be formed as a unit with the disposable strapmembers 19 and in which instance the strap member may be directlyattached, such as by heat-sealing to itself, thereby obviating thenecessity of the previously discussed post member 47 at the ends and thepreviously discussed yoke member 15a may be provided with suitableattachment means, such as hooks or the like, which are directlyinsertable into the perforations 46 of the strap member 19.

FIG. 6 illustrates, in schematic form, an energization circuit suitablefor use with the various servo-positioning means, i.e., M1, M2, M3 andM4, utilized in the instant apparatus. Various precision controlcircuits are known, such as disclosed in U.S. Pat. No. 2,846,630 or inU.S. Pat. No. 3,513,370, both of which patents are incorporated hereinby reference, and can be incorporated into a suitable motor means toallow precise and speedy positioning of a member driven by such motormeans.

Briefly described, the energization circuit shown can include a smallreversible DC motor for accurately positioning a shaft, an electronicswitching system for controlling deenergization of the reversible DCmotor, and a differential amplifier system for controlling the operationof the electronic switches. The differential amplifier system comprisesa reference network and an error network, each comprising two stages ofamplification connected across a single source of supply. Thedifferential outputs of the networks are used to control the output of adriver-amplifier which, in turn, selectively controls the operation ofthe two electronic switches to control the energization of thereversible DC motor. Preferably, the electronic switches comprises aPNP-type transistor and an NPN-type transistor having interconnectedemitters, and each having a base connected to a common point in thedifferential amplifier network. When the conductivity of thedriver-amplifier is increased by the differential output, one of thetransistor switches becomes conductive and the motor is energized in onedirection. When the conductivity of the driver-amplifier is decreased,the other transistor switch becomes conductive and the motor isenergized in the other direction. In either case, the motor will alwaysdrive an element in the error network until such time as the referenceand error networks are balanced and then the motor is again deenergized.This type of transistorized servo-positioner systems is extremelyaccurate and fast thereby allowing precisely tine adjustment of thevarious driven elements.

As indicated before, suitable electrical insulators may be positionedbetween those elements in contact with the patient and/or are inrelative proximity to contact by operating personnel to insure that noshort circuits or the like occur. As will be appreciated, the disposablestrap member 19 is an insulator member which completely isolates theelectrical system of the apparatus from the patient. Also, suitabledisposed parallel energization circuits can be provided to avoid dangersof nonoperability of the main circuits and, as is common with mostelectronic surgery equipment, an alternate power source can also beprovided in working relation to the energization circuits wherebycontinuous operation of the retraction apparatus is insured.

In summation, it will be seen that the invention provides a surgicalretraction device for use away from an operating table, comprising, amovable support means selectively positionable along the operatingtable, an upright assembly mounted on said support means for selectiverotation about said vertical axis, a boom assembly mounted for selectivepivotal movement about said upright assembly and including an axiallymovable arm member having a securing end, at least one disposable strapmember attached to said securing end of the arm member and having a freeend, a retraction instrument attached to said free end of the strapmember, and means for speedily and precisely positioning at least thearm member.

Certain changes and modifications in the practice of the presentinvention can readily be made without substantially departing from theintended spirit and scope of the invention. Therefore, it is to be fullyunderstood that the invention is not to be limited or in any wayrestricted to the preferred embodiments thereof which are set forth inthe foregoing description and specification; rather, its scope andspirit is to be construed and interpreted in light of the appendedclaims.

I claim as my invention:

1. In combination, a surgical operating table and a surgical retractiondevice for use therewith, said surgical retraction device comprising amovable support means selectively positionablealong the operating table,an upright assembly rotatably mounted on said support means forselective rotation about a longitudinal axis thereof, a boom assemblypivotally mounted on said upright assembly for selective pivotalmovement about said upright member, said boom assembly including alongitudinally movable arm member having a securing end, at least onedisposable strap member attached to said securing end and having a freeend, a retraction instrument attached to said free end of the strapmember and means for speedily and precisely controlling the position ofat least the arm member.

2. A surgical retraction device as defined in claim 1 wherein the meansfor speedily and precisely positioning includes a transistorizedprecision servo positioner including a reversible DC motor coupled inworking relation to said arm member.

3. A surgical retraction device as defined in claim 2 wherein themovable support member, the upright assembly and the arm member are allconnected in a working relation to the precision servo positioner, saidpositioner being adapted to be actuated from a remote position.

4. A surgical retraction device as defined in claim 1 wherein thesupport means is provided with lockable wheel members for selectivelymoving the support means along a path, and track means are providedrecessed into a floor along said path for positively guiding said wheelmembers along said path.

5. A surgical retraction device as defied in claim 1 wherein thedisposable strap member is composed of a synthetic resin material havinga predetermined tensile strength.

6. A surgical retraction device as defined in claim 5 wherein thedisposable strap member and the retraction instrument comprise a singlesterilizable and disposable unit.

7. A surgical retraction device as defined in claim 5 wherein thedisposable strap member is provided with a plurality of substantiallyuniformly spaced perforations along the length thereof and a meansadjacent the ends thereof for mating with one of said perforations forapproximate adjustment of the length thereof.

8. A surgical retraction device as defined in claim 1 wherein anattachment means is fixedly secured to the securing end of the armmember, said attachment means having an adjustable tensioning means anda warning means in working relation therewith, said tensioning meanshaving one end fixedly attached to said attachment means and the otherend being free to move in response to tension on the strap member, saidwarning means being actuated by contact with said tensioning means.

9. A surgical retraction device as defined in claim 1 wherein aplurality of strap members are attached and uniformly spaced along thesecuring end of the arm member.

10. In combination, a surgical operating table and a surgical retractiondevice for use therewith, said surgical retraction device comprising,

a support member adapted for selective movement along a floor so as tobe selectively positioned along the operating table an upright assemblyrotatably mounted on said support member for selective angularpositioning in respect to said support member, and upright assemblyincluding a linearly movable rod member and a precisionservo-positioning means for selectively and accurately moving said rodmember along the vertical axis of said upright assembly,

a boom assembly pivotally attached to an upper portion of said uprightassembly for selective angular positioning thereof in respect to thevertical axis of said upright assembly, said boom assembly including alinearly movable arm member and a precision servo-positioning means forselectively and precisely moving said arm member along a longitudinalaxis of said boom assembly, said precision servo-positioning means beingadapted for actuation from a remote position, an attachment meansfixedly secured to an end of said arm member, said attachment meanshaving an adjustable tension means and a warning means in workingrelation therewith, said tension means having one end fixedly attachedto said attachment means and the other end thereof free to move inresponse to tension, said warning means being fixed on said attachmentmeans remote from said arm member and being actuated by contact withsaid tension means, a yoke member fixedly attached to said otherend ofthe tensioning means and having a portion thereof extending transverselyto said arm member,

a plurality of disposable strap members attached along said transverselyextending portion of the yoke member in a spaced manner from each other,said strap members being composed of a synthetic resin material having apredetermined tensile strength, and

a plurality of retraction instruments each individually attached to afree end of a strap member of said plurality of strap members forinsertion into a surgical incision,

11. A surgical retraction device as defined in claim 1 wherein theupright assembly is selectively movablealong the longitudinal axisthereof.

12. A surgical retraction device as defined in claim l1 wherein theupright assembly includes a vertical standard rotatably mounted on thesupport means and an auxiliary rod member supported on said verticalstandard and linearly movable along the longitudinal axis of saidupright assembly for selectively positioning the boom assembly.

Anna: Ann"

1. In combination, a surgical operating table and a surgical retractiondevice for use therewith, said surgical retraction device comprising amovable support means selectively positionable along the operatingtable, an upright assembly rotatably mounted on said support means forselective rotation about a longitudinal axis thereof, a boom assemblypivotally mounted on said upright assembly for selective pivotalmovement about said upright member, said boom assembly including alongitudinally movable arm member having a sEcuring end, at least onedisposable strap member attached to said securing end and having a freeend, a retraction instrument attached to said free end of the strapmember and means for speedily and precisely controlling the position ofat least the arm member.
 2. A surgical retraction device as defined inclaim 1 wherein the means for speedily and precisely positioningincludes a transistorized precision servo positioner including areversible DC motor coupled in working relation to said arm member.
 3. Asurgical retraction device as defined in claim 2 wherein the movablesupport member, the upright assembly and the arm member are allconnected in a working relation to the precision servo positioner, saidpositioner being adapted to be actuated from a remote position.
 4. Asurgical retraction device as defined in claim 1 wherein the supportmeans is provided with lockable wheel members for selectively moving thesupport means along a path, and track means are provided recessed into afloor along said path for positively guiding said wheel members alongsaid path.
 5. A surgical retraction device as defied in claim 1 whereinthe disposable strap member is composed of a synthetic resin materialhaving a predetermined tensile strength.
 6. A surgical retraction deviceas defined in claim 5 wherein the disposable strap member and theretraction instrument comprise a single sterilizable and disposableunit.
 7. A surgical retraction device as defined in claim 5 wherein thedisposable strap member is provided with a plurality of substantiallyuniformly spaced perforations along the length thereof and a meansadjacent the ends thereof for mating with one of said perforations forapproximate adjustment of the length thereof.
 8. A surgical retractiondevice as defined in claim 1 wherein an attachment means is fixedlysecured to the securing end of the arm member, said attachment meanshaving an adjustable tensioning means and a warning means in workingrelation therewith, said tensioning means having one end fixedlyattached to said attachment means and the other end being free to movein response to tension on the strap member, said warning means beingactuated by contact with said tensioning means.
 9. A surgical retractiondevice as defined in claim 1 wherein a plurality of strap members areattached and uniformly spaced along the securing end of the arm member.10. In combination, a surgical operating table and a surgical retractiondevice for use therewith, said surgical retraction device comprising, asupport member adapted for selective movement along a floor so as to beselectively positioned along the operating table, an upright assemblyrotatably mounted on said support member for selective angularpositioning in respect to said support member, and upright assemblyincluding a linearly movable rod member and a precisionservo-positioning means for selectively and accurately moving said rodmember along the vertical axis of said upright assembly, a boom assemblypivotally attached to an upper portion of said upright assembly forselective angular positioning thereof in respect to the vertical axis ofsaid upright assembly, said boom assembly including a linearly movablearm member and a precision servo-positioning means for selectively andprecisely moving said arm member along a longitudinal axis of said boomassembly, said precision servo-positioning means being adapted foractuation from a remote position, an attachment means fixedly secured toan end of said arm member, said attachment means having an adjustabletension means and a warning means in working relation therewith, saidtension means having one end fixedly attached to said attachment meansand the other end thereof free to move in response to tension, saidwarning means being fixed on said attachment means remote from said armmember and being actuated by contact with said tension means, a yokemember fixedly attached to said other end of the tensioning means andHaving a portion thereof extending transversely to said arm member, aplurality of disposable strap members attached along said transverselyextending portion of the yoke member in a spaced manner from each other,said strap members being composed of a synthetic resin material having apredetermined tensile strength, and a plurality of retractioninstruments each individually attached to a free end of a strap memberof said plurality of strap members for insertion into a surgicalincision.
 11. A surgical retraction device as defined in claim 1 whereinthe upright assembly is selectively movable along the longitudinal axisthereof.
 12. A surgical retraction device as defined in claim 11 whereinthe upright assembly includes a vertical standard rotatably mounted onthe support means and an auxiliary rod member supported on said verticalstandard and linearly movable along the longitudinal axis of saidupright assembly for selectively positioning the boom assembly.